If the angle is mesure in RADIANS then the arc is given by r. So first convert 81 degrees to radians, then multiply by r which is 10 x 81=810
Yes, 13 is correct
If you draw the right triangle, the two legs will be 5 and 12.
5 and 12 are parts of a Pythagorean triple. 13 completes the triplet.
49.26 because 90-40.74=49.26
